Field of the Disclosure
The present disclosure relates generally to a plunger assembly for use with a syringe adapted for delivery of a fluid. More particularly, the present disclosure relates to a plunger assembly for connecting a plunger rod to a stopper or plunger that can be assembled at the point of use.
Description of the Related Art
Syringe assemblies, and in particular hypodermic syringes, are well known in the medical field for dispensing fluids, such as medications. A conventional syringe typically includes a syringe barrel with an opening at one end and a plunger mechanism disposed through the opposite end. The plunger mechanism typically includes a plunger rod extending through the barrel, with a plunger head or stopper disposed at the end of the plunger rod within the syringe barrel, and with a finger flange at the other end of the plunger rod extending out of the syringe barrel. In use, the plunger rod is retracted through the syringe barrel to aspirate or fill the syringe barrel with a fluid, such as a medication, with the plunger rod extending out from the rear end of the syringe barrel. For delivery of the medication to a patient, the opening of the syringe barrel is adapted for fluid communication with a patient, such as through a hypodermic needle fitted at the front end of the syringe barrel or through a luer-type fitting extending from the syringe barrel for attachment with a fluid line of a patient. Upon the user applying a force to depress the plunger rod and stopper through the syringe barrel towards the front end of the syringe barrel, the contents of the syringe are thereby forced out of the syringe barrel through the opening at the front end for delivery to the patient. Such an operation is well known in the medical field, and medical practitioners have become well accustomed to the use of such common fluid delivery procedures through standard syringes.
Conventional syringes are well known in the medical field to be used in connection with a vial of a medication, where the user collects or draws the fluid into the syringe immediately prior to injection and delivery of the fluid to the patient. Commonly, hypodermic syringes may be packaged as “pre-filled” devices, wherein the syringe is pre-filled with medication prior to being packaged and delivered to the patient. In this manner, the need for the user to fill the device prior to injection is eliminated, thereby saving time and maintaining consistent volumes for delivery.
However, packaging of such pre-filled syringes may be difficult, since the plunger rod extends beyond the proximal end of the syringe barrel requiring additional space in storage cabinets or automated dispensing cabinets. Therefore, there is a need for a plunger assembly that can be assembled at the point of use, so that the storage volume of the packaged pre-filled syringe is effectively reduced. Specifically, a user should be able to connect the plunger rod to a portion of the syringe just prior to performing a fluid injection. Accordingly, the storage volume of the syringe as a whole has a volume and aspect ratio substantially identical to the syringe barrel. In a storage position, there is no plunger rod extending beyond the proximal end of the syringe barrel. Such a plunger assembly including a plunger rod that can be attached to the syringe at the point of use is disclosed herein.